Electric lamp



Dec. 19, 1933. G PU PALA 1,940,509

ELECTRIC LAMP Filed Oct. 22, 1931 VEN TOR George :4

a a BY p ATTORNEY? Patented Dec. 19, 1933 UNITED STATES PATENT OFFICE This invention relates to new and useful improvements in an electric lamp.

The invention has for an object the construc tion of an electric lamp which is characterized by the provision of a plurality of illuminating wires arranged in a fashion so that one or more may become fused while the remaining ones continue to burn and give illumination.

As another object of this invention it is proposed to construct the illuminating wires of diiferent thickness or in groups of different thickness so as'to eliminate the possibility of all of them burning out at the same time.

A still further object 'of this invention is to construct a lamp with a plurality of illuminating wires arranged over a short distance so as to reduce to a minimum breakage of the wires due to vibration.

As another object of this invention it is proposed to provide spare illuminating wires within the lamp and arranged so as to be movable into operative positions from the exterior of the lamp.

'Furthermore, as another object of this invention it is proposed to. construct a lamp with a plurality of radial arms, to arrange operative illuminating wires between certain of said arms, and to support spareilluminating wires upon the other of said arms, and provided with means capable of being magnetically acted upon from the exterior for bringing the spare illuminating wires into use. A stillfurther object of this invention is the construction of a safety lamp of the class (19- scribed which is of simple, durable construction, dependable in use and efficient in action and which can be manufactured and sold at areasonable cost.

For further comprehension of the invention;

and of the objects and advantages thereof, reference will be had to the following description and accompanying drawing, and to the appended claims in which the various novel features of the invention are more particularly set forth.

In the accompanying drawing forming a material part of this disclosure:

Fig. 1 is a schematic illustration of an electric lamp constructed according to this invention.

Fig. 2 is a schematic wiring diagram of the radial arms and illuminating wires of a modified form of electric lamp.

Fig. 3 is a fragmentary view similar to a portion of Fig. 1 but illustrating a modified arrangement.

Fig. 4 is a fragmentary enlarged detailed view of a portion of Fig.' 3. p

The safety electric lamp, according ,to this invention, comprises a vacuum'bulb 10 .support ing a contact shell 11 and an end contact 12. An

ductors 13 and 14 respectively are supported from a central stem portion 15of the bulb 10. The lamp has acircuit which connects in series the contact end 12, the upper "groupof radial conductors 13, illuminating wires 16, the lower group of radial conductors 14 and the contact shell 11. This circuit'is formed by a wire 17 whichextends from the contact end 12 to the central common point of the radial arms 13 and a second 3 wire 18,-which extends from the contact shell 11 to the common central point of theradial arms 14:.

The radial conductors 13 and 14 are of heavier material than the illuminating "wires 16.

In Fig. 2 a modification "of the invention has been disclosed in which the radial arms 13' and 14 are schematically shown so that "the arrangement of the illuminating wires between them may be j I shortening its life. For this reason, it is proposed to arrange the radial conductors 13 and 14 close together and still the necessary candle-power of g the lamp may be obtained byreason of the ohmic summation of the illuminating wires. Furthermore, the wire l'l-should be of different gauges for the purpose of preventing thepossibility of their blowing at one time. had by desi ning the wires 16 of different sizes is that they will burn out a number of hours apartfrom each other and in this manner give proper warning so that the lamp may be replaced before all of the wires burned out and the lamp is completely extinguished. A convenient arrangement of the lamp would be one in which alternate wires are of the same gauge and other wires of a different gauge.

In Figs. 3 and 4, another modification of the invention has been disclosed in which spare illuminating wires are provided which normally are not illuminated but can be moved into opera- Another advantage I 60 upper and a lower group of spaced radial contive position magnetically from the exterior. The lamp is shown provided with a plurality of top radial conductors 13 and by the radial conductors 20 and 21 respectively. Illuminating wires 16 are permanently attached between certain of the conductors 13 and. the conductors 20. Other idler illuminating wires 22 are permanently attached upon the remaining upper radial con-' ductors I3 and at the bottom end are provided with catches 23 capable of engagement with the free ends of the radial arms 21. These catches are in the form of resilient plates having central openings 24 capable of engaging upon arrowheads 25 formed on the ends of the radial arms 21:. The plates 23 are of iron or similar metal which may be magnetically attracted from the exterior of the lamp so that the idler illuminating'wires may be placed into use.

embodiment of my invention, it is to be understood. that .I-do not limit myself to the precise consanction"'aereinnsaosea an the'rightis re-' served, to all changes and modifications coming within the sccp'e'of the'invention as de'fined in the appende'd claims.

Having thus described my invention, what I claim as new, and desire'to States Letters Patent i.'s :f 3

1; An electric lamp, comprising a vacuum bulb ;supporting an end contact and a shell contact, a

groupof spaced. upper and lower radial conductors within said bulb, means for supporting said cpnductors from saidbulb, a circuit including in series" said. end contactfthe upper of the group ofradialconductors, illuminating wire, the lower group of radialconductors, and said contact shell,

spare illuminating wires depending from certain of said upper radial conductors, and catches on the free ends of. said spare wires capable of coaction'with the'free ends of certain of the lower ial. conductors magnetically engageable from theexteri'or, 1

[2."A1'1Q6l6lctric lamp,.comprising a vacuum bulb supportingf'an end contact and, a shell contact,

roupof fspaced'upp'er and lower radial conduct within said bulbf'andmeans for supporting said'coriductors'iromsaid bulb, a circuit including in series saidi endcontact, the upper of the groupcf ,radial "conductors, illuminating wire, the

low rgroup. of radial conductors, and said contact "sli ell', spare illuminating, wires depending from certain offsaidupper radial conductors, remote controlfoperable catches on the free ends of said spare wires capable of co-action with the free ends ofjcertain of the lower radial conductors;v

3. Anlelectriclamp, comprising a vacuum bulb supporting'anend contact and a shell contact, agrou'p 'oi" s'paced'upper and lower radial conductors within said, bulb, means for supporting said conductors from said bulb, a circuit including in'fseries'saidend contact, the upper of the group, of radial -conductors, illuminating wire, the

secure by United series said end contact, the upper of the group of radial conductors, illuminating wire, the lower group of radial conductors, and said contact shell, spare illuminating wires depending from certain of said upper radial conductors, and catches on the. free ends of said spare wires capable of co- While I have shown and described the preferred,

action withthe free ends of certain of the lower radial conductors magnetically engageable from the exterior, said catches comprise a plate having acentral opening, and an arrowhead on the lower radial. conductors engageable in saidcentral opening." v v p 5. An electric lamp, comprising a vacuum bulb supporting an end contact and a shell contact, a group of spaced upper and lower radial, conductors within said bulb, means for supporting said conductors from said bulb, a circuit including in series said endcontact, the upper. of the group of radial conductors, illuminating wire, the lower group of radial conductors, and said contact shell, spareilluminatin'g wires depending from certain of said upper radial conductors, and catches on the free endsof said spare wires capable of co-action with the free endsof certain of the lower radial conductors magnetically engageable from the exterior, said catches comprise a'plate having a centralopening, and an arrowhead on the lower radial conductors engageabl insaid central opening, said plate being made of resilient material' R I 6. An electric lamp, comprising a vacuum bulb supporting an endcontact. and a shell contact, agroup of spaced upperand lower radial conductors within said bulb, means for supporting said conductors from said bulb, a circuit includingin series said end contact, the upper. or the group of radial conductors, illuminating wire, the lower group, of radial conductors, and said contact shell, spare illuminating wires depending. from certain of said upper radial conductors, and catches on the free ends. of said spare wires capableiotcoaction withthe free ends of certain of thelower radial conductors magnetically engageable from the exterior, said catches comprise a. plate having 

